For the convenience of operators and safety of navigation, various detection devices, such as fish finders, sonar; radars, and GPS units are equipped on a vessel, and this type of detection devices are typically interconnected to form a network system on the vessel. Thus, the typical vessel may equip a plurality of the same type of the detection devices.
Japanese Unexamined Patent Application Publication No. 2004-150872 discloses a vessel that includes a plurality of ultrasonic detectors (e.g., fish finders or sonar), and a plurality of indicators for the detectors (the indicator may be integrally provided or may be separately provided to the detection device).
In the vessel instrument network system of Japanese Unexamined Patent Application Publication No. 2004-150872, navigation data generated by the detection devices can be selectively displayed on any of the indicators by a user's selection. Thus, the selection must be made by the user manually, and must be made considering which detection device provides the best possible results, etc. In addition, the detection devices that generate the same type of the navigation data may not be operated at the same time. Therefore, in this case, one of the detection devices must be manually disabled or disconnected from the network, and thereby further requiring the operator to perform troublesome operations.